Device for the production of photographic copies by the silver-salt diffusion process



June 9, 1964 A. CORONA 3,136,238

DEVICE FOR THE PRODUCTION OF PHOTOGRAPHIC COPIES BY THE SILVER-SALT DIFFUSION PROCESS 3 Sheets-Sheet 1 Filed Dec. 15, 1961 KVENTOR;

FFTORIJEYS June 9, 1964 A. CORONA DEVICE FOR THE PRODUCTION OF PHOTOGRAPHIC COPIES BY THE SILVER-SALT DIFFUSION PROCESS 5 Sheets-Sheet 2 Filed Dec. 15, 1961 June 9, 1964 CORONA 3,136,238

DEVICE FOR THE PRODUCTION OF PHOTOGRAPHIC COPIES BY THE SILVER-SALT DIFFUSION PROCESS Filed Dec. 15, 1961 5 Sheets-Sheet 3 IT T I I UI,

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United States Patent DEVICE FOR THE PRODUCTION OF PHDTO- GRAPHIC COPIES BY THE SILVER-SALT DIF- FUSION PROCESS Antonio Corona, Via Revere 15, Milan, Italy Filed Dec. 15, 1961, Ser. No. 159,562 Claims priority, application Italy Dec. 21, 1960 11 Claims. (Cl. 95--89) This invention relates to an apparatus for use in the production of photographic copies. may be used, for example, in a silver salt diffusion process.

According to the invention, there is provided a photocopying apparatus which comprises a tank, sheet feeding means whereby a positive and a negative sheet introduced into said tank can be fed to guide means adapted to guide said sheets through a developer liquid contained in the tank when the latter is in use, said guide means being arranged so as to ensure that the positive sheet is immersed in the liquid developer for a shorter period than the negative sheet and that the sheets-are brought together with their leading edges in register and with their sensitized surfaces facing each other, and sheet pressing mean for pressingsaid sheets together.

The guide means may be static or free to rotate and, advantageously, may comprise a first and second guide roller which are spaced apart immediately above the bottom of the tank, the guide rollers being arranged transverse to the direction of movement of the positive and negative sheets through the tank. Alternatively, two fixed guides preferably with rounded lower edges may be similarly disposed in the tank. The arrangement of the guide rollers or fixed guides is such that the negative sheet is fed under both guide rollers or fixed guides, whereas withdrawn.

It is to be understoodthat the positive and negative sheets are fed into the apparatus in such a manner that when the sheets are pressed together the sensitized faces thereof are brought into contact with each other.

The apparatus of the invention gives rise to the fol- (a) The quantity of developer liquid which has to be contained in the tank is minimized since the guide means are adapted to ensure that the sheets are immersed in the developer liquid near the bottom of the tank;

(b) The developer liquid is used quickly and to the maximum extent and there is avoided the inconvenience, common to the known apparatus, that the developer liquid is required in a large quantity and is inadequately used and/ or is utilized detrimentallyhaving been damaged by 'oxidization due to long exposure to the air;

ple with reference to three embodiments shown in the I accompanying drawings in which:

FIGURE 1 is a longitudinal cross-section of a photocopying apparatus in accordance with the invention;

Such an apparatus I 3,136,238 Patented June 9, 1964 FIGURE 4 is a longitudinal cross-section of a third embodiment;

FIGURE 5 is a fragmentary view of the sheet feeding means of, the embodiment shown in FIGURE 4 from the direction indicated by arrow S in FIGURE 4; and FIG- URE 6 is a fragmentary view of the sheet-feeding means shown in FIGURE 5 from the direction indicated by arrow F in FIGURE 4.

The partsof the three embodiments having the same function are marked with the same reference numerais. In the embodiment shown in FIGURE 1, the sheet feeding means consists of an upper and lower feedway and 16. A positive sheet A can be inserted by hand into A the upper feedway 15 and a negative sheet B can be inserted by hand into the lower feedway 16. At the outlet of the respective feedways, sheet B passes below a guide roller 5 and sheet A below a guide roller 5 the sheets being brought together in register at guide roller 5 with their sensitized surfaces facing each other. The sheets are moved forward together toa sheet pressing means comprising two pressure rollers 6 which are powered by an electric motor (not shown in the drawing) and which a longer period than the positive sheet A. In order that the leading edges of sheets A and B should match under roller 5 in spite of the difference in distance travelled, it is necessary to insert sheets A and B into the feedways 15 and 16 with their leading edges correctly spaced.

FIGURES 2 and 3 show a second embodiment which differs from the embodiment of FIGURE 1, in that the feedways are replaced by alternative sheet feeding means for the positive and negative sheets.

On the inside of a tank 7, near the bottom and immediately above the horizontal surface 7a of said tank, two spaced guide rollers 5 and 5 are provided as guide means. The pressing means comprises two pressure rollers 6 which are powered by an electric motor (not shown in the drawing), the pressing means being situated along the upper part of the wall 7b of the tank. Superposed slits 1 and 2 for introducing the two sheets A and B into the apparatus are situated in the upper portion of the opposite wall 7c. The sheets A and B are kept apart by a baffle 11. In the direction in which the sheets are inserted, there is a separator plate provided with a flat, horizontal surface 4a which leads on to a downwardly sloping surface 411 which in turn abuts a guide plate 4c. The portion 4b of the separator plate lies in the plane of the nip of a pair of feed rollers 3 which have corresponding portions of their length of a reduced diameter. The peripheral speed of the these feed rollers may be synchronized with that of the pressure rollers 6.

Plates 4b and 4c are provided with slots 12 (FIGURE 3) which correspond to those parts of the feed rollers 3 that come into contact with each other, said parts having a larger diameter than the remaining parts thereof. The Walls defining the slits 1 and 2 are made of a transparent material so that markers T and T in the baflie, are visible. The embodiment illustrated in FIGURES 2 and 3 can be operated in the following manner:

The two sheets, positive A and negative B, are inserted into the slits 1 and 2 respectively so that the leading edge of the sheet A' coincides with marker T and the leading edge of the sheet B with marker T The sheets are then,

simultaneously, and in the spaced relationship, pushed forward until the sheet A (above plate 4) and the sheet B (below plate 4), pass bteween the feed rollers 3. The two sheets now proceed at apredetermined speed set by the speed of rotation of the rollers 3.

Sheet A, afterleaving the plate 4c passes above the roller and is immersed in the developer liquid, passing under the roller 5 where it comes into contact with sheet B. I

Sheet B is guided downwards from plate 4c and is immersed in the developer liquid whilst passing under roller 5 and continuing to roller 5 where it comes into contact with sheet A. The two sheets then move forward and pass between the pressure rollers 6 of the pressing means.

As a result of the above described arrangement, sheet B remains immersed in the developer liquid for a greater length of time than sheet A. The distance travelled by the sheets A and B and the positions of the markers T and T are such that the sheets, which come into contact under roller 5 have their leading edges in register when passing betweeen' the pressure rollers 6.

The developer liquid contained in the tank is sufiicient for the preparation of a limited number of copies. After obtaining said copies, the bath is exhausted and has to be replaced by a fresh bath. This can be done, for example, by having ready quantities of developer liquid in suitable plastic containers.

A means of replenishing the bath is indicated in FIG- URE 2 in which the tank is provided with a lid having a pocket 8 with a bored bottom and a cutting point 9 protruding from the bottom. The pocket is covered with a hinged portion 10 which is adapted so as to carry a bag of fresh developer liquid. When the bag, fixed to the lid 10, is lowered it presses against the cutting point 9 at the bottom of the pocket and is thereby broken, the contents of the bag being collected in the tank below. It should be noted that although the bag 10 is broken by means of cutting point 9, the bag or other suitable container which may be employed, may be punctured by any suitable device known per se.

Referring now to the embodiment shown in FIGURES 4, 5 and 6, sheets A and B are introduced into the tank 7 by deflection members 17 and 18 which deliver the sheets separately to two primary feed rollers 19 and 19 The roller 19 is supported by the tank rotating round a stationary axis, the roller 19 has the pivots slidable in guideways 26, which are foreseen in the side walls of the tank; and the two rollers 19 and 19 are axially separable by overcoming the power of springs 20. The two rollers 19 and 19 are separated by means of two series of short secondary rollers 21 and 22, each of them being provided with corresponding pivots supported by arms 23 whose hub rotates on a transverse shaft 24 which, in turn, in supported by, and fixed to, the tank. Both rollers 21 and 22 are also provided with pivots, supported by two adjacent arms 23.

The series of rollers 21 and 22 have their axes parallel to the axes of the rollers 19 and 19 but are slightly displaced with respect to each other, so that the series 21 contacts and co-operates with the roller 19 and the series 22 contacts and co-operates with the roller 19 the rollers of the respective roller systems so formed being held in contact by the springs 20. As already indicated, the two deflection members 17 and 18 lead on to, respectively, the roller systems formed by the pairs of contacting and co-operating rollers 21/19 and 22/19 which systems constitute the sheet-feeding means for the sheets A (positive) and B (negative). By a known means of transmission, for example chain or gearing the rollers 19 and 19 are positively'driven at speeds which are in synchronized relationship to that of pressure rollers 6 of the pressing means. Thus, for example, if roller 19 is driven at a slower peripheral speed than roller 19 e.g., by forming the rollers 19 and 19 with different diameters but driving them at the same rate of revolution, it is possible to match the leading edges of the negative and positive sheets at roller 5 without the necessity of inserting the said sheets correctly spaced, as described in connection with the embodiment shown in FIGURE 2.

The tank is provided with a lid having a funnel 25 through which fresh developing liquid can be poured into the tank. Such liquid can, for example, be kept in a screw-top container and poured in after removing the used liquid. A further advantage afforded by the embodiment shown in FIGURES 4, 5 and 6 is that it offers a better grip of the two individual sheets A and B, owing to the reciprocal continuity and articulation of the rollers 21 and 22 and of the resulting uniformity of pressure.

In the embodiments described, with reference to the accompanying drawings, the two guide rollers 5 and 5 may be replaced by two fixed transverse guides which preferably are provided with suitable rounded lower edges.

What I claim is:

1. In a photocopying apparatus wherein negative and positive sheets are immersed together in a developing solution and brought into engagement to transfer a print image to said positive sheet, the herein invention comprising in combination, a hollow tank member, said tank having means on opposite sides thereof to accommodate entry and exit of said sheets respectively, said tank having a well formation formed therein and said well formation adapted to contain developing solution, sheet feed means capable of introducing positive and negative sheets separately into said solution at differing angular paths respectively, first and second roller means disposed within said well portion and spaced apart therein lying in a common plane, said first and second roller means adapted to be immersed within said solution and disposed respectively, to engage said negative and positive sheets substantially immediately upon entry thereof into the solution, said negative sheet adapted to be passed below both said first and second roller means and said positive sheet adapted to be passed below only said second roller means, said second roller means spaced from the bottom of the well so as to cause engagement of said sheets simultaneously with passage of same therebelow, and pressure exerting means adjacent said exit adapted to receive said sheets immediately prior to exit of same from the tank.

2. The invention claimed in claim 1 in which said feed means includes plate means for diverting the paths of said positive and negative sheets.

3. The invention as claimed in claim 1 in which said feed means includes battle means for diverting the paths of said positive and negative sheets, said baflle means comprising a pair of upper plate members disposed within said tank to define a descending pathway adapted to receive said positive sheet and terminating closely adjacent said second roller means, and at least one additional plate member descending at an angle divergent tosaid upper plate members and cooperating with the side of the tank to define a pathway adapted to receive said negative sheet and terminating closely adjacent said first roller means.

4. The invention as claimed in claim 1 in which said feed means includes baffle means adapted to divert the path of entry of said sheets to a downwardly but divergent path, whereby the negative and positive sheets enter the developing'solution immediately adjacent the first and second roller means.

5. The invention as claimed in claim 1 in which said feed means includes baifie means and cooperative belt means immediately adjacent said baffie means adapted to divert the path of entry of said sheets to a downwardly but divergent path, whereby the negative and positive sheets enter the developing solution immediately adjacent the first and second roller means.

6. The invention as claimed in claim 1 in which said entry means comprises, aperture means formed in the side of said tank and defining a pair of superimposed slit openings and a bathe member therebetween, a separator plate disposed interior of said tank and immediately adjacent said battle member, said separator plate having a horizontal portion and a downwardly sloping portion, a pair of feed roller members mounted for rotation immediately adjacent said downwardly sloping portion and having the axes thereof superimposed to form a nip therebetween, said roller members having selected portions of increased diameter, said downwardly sloping portion adapted to lie in the same plane as the said nip, a sloping guide plate disposed on the opposite side of said nip, with the edges thereof in abutting relation to said downwardly sloping portion, said guide plate being canted at a steeper angle relative said downwardly sloping portion, the abutting edges or" said separator plate and said guide plate having a plurality of slots adapted to receive said selected portions of said feed roller members whereby the same are engaged therein to grasp and propel said positive and negative sheets at divergent angles respectively toward said well.

7. The invention as claimed in claim 1 in which said entry means comprises aperture means formed in the side ofsaid tank and defining apair of superimposed slit openings, and said sheet feeding means adapted to receive sheets from said apertures and comprising, at least a pair of primary roller members having a common axial plane and disposed interior of said tank adjacent said aperture means, a pair of parallel series ofsecondary rollers separating said primary rollers, one of said series of secondary rollers cooperating wth one of said primary rollers to form sheet-feeding means for the negative sheet, the other of said series of secondary rollers cooperating with the other of said primary rollers to form sheet feeding means for the positive sheet, each series of rollers capable of directing its respective sheet at relatively diverging to cover said pocket and having bag holding means thereon, thereby to permit introduction of fluid into the well portion by pressing the bag-containing lid against the perforating means within the pocket.

9. The invention as claimed in claim 3 in which the tank is provided with a lid, the lid having a depressed pocket formed therein, said pocket being provided with a bored bottom and perforating means disposed within said pocket, said lid having a hinged portion adapted to cover said pocket and having bag holding means thereon, thereby to permit introduction of fluid into the well portion by pressing the bag-containing lid against the perforating means within the pocket.

10. The invention as claimed in claim 5 in which the tank is provided with a lid, the lid having a depressed pocket formed therein, said pocket being provided with a bored bottom and perforating means disposed within said pocket, said lid having a hinged portion adapted to cover said pocket and having bag holding means thereon, thereby to permit introduction of fluid into the well portion by pressing the bag-containing lid against the perforating means within the pocket.

11. The invention as claimed in claim 6 in which the tank is provided with a lid, the lid having a depressed pocket formed therein, said pocket being provided with a bored bottom and perforating means disposed within said pocket, said lid having a hinged portion adapted to cover said pocket and having bag holdingmeans thereon, thereby to permit introduction of fluid into the well portion by pressing the bag-containing lid against the perforating means within the pocket.

5 References Cited in the file of this patent UNITED STATES PATENTS 2,582,156 Peterson Jan. 8, 1952 2,742,838 Paulas Apr. 24, 1956 2,810,331 Van Der Grinten Oct. 22, 1957 2,925,025 Conner Feb. 16, 1960 FOREIGN PATENTS 7 544,284 Belgium Jan. 31, 1956 

1. IN A PHOTOCOPYING APPARATUS WHEREINNEGATIVE AND POSITIVE SHEETS ARE IMMERSED TOGETHER IN A DEVELOPING SOLUTION AND BROUGHT INTO ENGAGEMENT TO TRANSFER A PRINT IMAGE TO SAID POSITIVE SHEET, THE HEREIN INVENTION COMPRISING IN COMBINATION, A HOLLOW TANK MEMBER, SAID TANK HAVING MEANS ON OPPOSITE SIDES THEREOF TO ACCOMMODATE ENTRY AND EXIT OF SAID SHEETS RESPECTIVELY, SAID TANK HAVING A WELL FORMATION FORMED THEREIN AND SAID WELL FORMATION ADAPTED TO CONTAIN DEVELOPING SOLUTION, SHEET FEED MEANS CAPABLE OF INTRODUCING POSITIVE AND NEGATIVE SHEETS SEPARATELY, FIRST AND SECOND ROLLER MEANS DISPOSED WITHIN SAID WELL PORTION AND SPACED APART THEREIN LYING IN A COMMON PLANE, SAID FIRST AND SECOND ROLLER MEANS ADAPTED TO BE IMMERSED WITHIN SAID SOLUTION AND DISPOSED RESPECTIVELY, TO ENGAGE SAID NEGATIVE AND POSITIVE SHEETS SUBSTANTIALLY IMMEDIATELY UPON ENTRY THEREOF INTO THE SOLUTION, SAID NEGATIVE SHEET ADAPTED TO BE PASSED BELOW BOTH SAID FIRST AND SECOND ROLLER MEANS AND SAID POSITIVE SHEET ADAPTED TO BE PASSED BELOW ONLY SAID SECOND ROLLER MEANS, SAID SECOND ROLLER MEANS SPACED FROM THE BOTTOM ON THE WELL SO AS TO CAUSE ENGAGEMENT OF SAID SHEETS SIMULTANEOUSLY WITH PASSAGE OF SAME THEREBELOW, AND PRESSURE EXERTING MEANS ADJACENT SAID EXIT ADAPTED TO RECEIVE SAID SHEETS IMMEDIATELY PRIOR TO EXIT OF SAME FROM THE TANK. 